Conventionally, the phase of a motor is managed and controlled by a motor drive IC (Integrated Circuit), which, when being used, sequentially stores values corresponding to the current phase positions of the motor.
In the case where a motor rotates and moves at predetermined phase positions (herein, set to be ‘1’-‘4’ as an example), in order to manage phases of the motor, the motor drive IC stores the current phase positions ‘1’-‘4’ in the form of numeric values. The motor drive IC updates the values when outputting a pulse signal to the motor.
When an apparatus provided with a motor and a motor drive IC (hereinafter referred to as a drive IC) for controlling and managing the motor enters a power-saving mode (also called as a sleep mode), the power supply to the drive IC is cut off, and the phase values stored in the drive IC are reset. If the apparatus enters the power-saving mode when the current phase position of the motor is, for example, ‘2’, the phase value of the drive IC is reset to be, for example, an initial value ‘1’ when the apparatus resumes from the power-saving mode. Thus, when the power supply to the drive IC is cut off due to the power-saving mode and the like, the phase value managed by the drive IC is inconsistent with the actual phase position of the motor. In the conventional apparatus, the motor is driven to move to make the phase position thereof to be the initial position ‘1’ so that the phase value managed by the drive IC is consistent with the actual phase position of the motor.
However, time is needed for driving the motor to move. Moreover, the object device gaining power from the rotation of the motor moves as the motor moves. The moving is unnecessary and may cause timing deterioration of the object device. To avoid this situation, a method is proposed according to which the power supply to the drive IC is not cut off, however, this method is not power-saving.